Unless made with perfectly ripe tomatoes, tomato soup can often taste acidic. That’s why it’s often tamed with the addition of sugar. Here, the boost of sweetness comes from carrots instead, which also thicken the soup and add a nice, velvety texture. Pair with grilled cheddar cheese sandwiches cut into sticks for dipping.
Heat the oil in a large saucepan over medium heat. Add the onion and carrots. Cover and cook until very soft, about 10 minutes, uncovering the pot to stir occasionally.
Add the garlic and cook until fragrant, about 30 seconds. Stir in the tomatoes and 3 1/4 cups water, along with the salt and pepper. Bring to a boil over medium-high heat.
Reduce the heat to medium and simmer for 10 minutes. Remove the soup from the heat. Stir in the basil.
Working in two batches, carefully transfer the soup to a blender and blend until smooth and creamy. Return the soup to the pot, reheat if necessary. Ladle into individual bowls and serve. If packing in a lunch box, use a thermos.